Arrangement for counting signals of specific significance



Oct. 29, 1968 T. STUTZ I I 3,408,484

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United States Patent Office 3,408,484 Patented Oct. 29, 1968 3,408,484 I ARRANGEMENT FOR COUNTING SIGNALS F SPECIFIC SIGNIFICANCE Theo Stutz, Zurich, Switzerland, assignor to Contraves A.G., Zurich, Switzerland Continuation-impart of application Ser. No. 279,039, May 6, 1963. This application Aug. 24, 1964, Ser. No. 392,998 Claims priority, application Switzerland, May 4, 1962, 5,370/62; Aug. 23, 1963, 10,417/63; Aug. 30, 1966, 12,559/ 66 11 Claims. (Cl. 235-92) ABSTRACT on THE DISCLOSURE Logic network means for use with multiphase binary signal generator means which, for a continuous change of a physical quantity, are adapted to generate a primary combination signal consisting of a first predetermined cyclic sequence of possible signal combinations for a positive unit change of the quantity and a second sequence for a negative unit change of the aforesaid physical quantity. This logic network includes a plurality of input lines corresponding in number to the number ofphases of the primary combination signal, a plurality of output lines corresponding in number to the number of the input lines, and a plurality of bistable switching means direct current coupled and logically interconnected both mutually and to the input lines and output lines, in such a manner that a secondary combination signal is generated, the secondary combination signal having the same number of phases and the identical sequence of binary signal combinations as the primary combination signal, but a secondary period which is an integral multiple of the primary combination signal period.

This is a continuation-in-part of my pending'applicationSer. No; 279,039, filed May 6, 1963 and entitled Arrangement for Counting Signals of Specific Significance and now abandoned.

The present invention concerns an apparatus for count- 1 ing the occurrence of certain signal elements or characteristics, for instance for counting the number of changes from the condition no (0) to the condition yes (L) in the case of yes-no signals which may be produced by suitable signal generators for the purpose of obtaining digital results when monitoring occurring changes of variable quantities. In other words, the invention concerns an apparatus for forming the algebraic sum of digits each representing a unit value of increments occurring within a change in positive or negative direction of a variable quantity.

Signal generators are known which change a given signal from no condition to yes condition alternatingly whenever during the variation of a variable quantity a change in the form of an increment of a certain predetermined unit value occurs. Also counting arrangements are known by means of which such signal changes are continuously counted so that, provided that the counting is carried out in the same direction as the positive or negative direction of the particular change of the monitored quantity, it is possible for instance to read from the counting arrangement at any time the actual value or magnitude of the particular quantity. In order to provide for a high counting speed these known counting ar-' rangements are in most cases electronic counters for counting the sequences of electricalsignals. However, it has bcenfound, thatthe'great inconvenience exists that spurious signals which are practically unavoidable, may frequently imitate or be taken as a yes si nal ofthe generator so that this spurious signal'would be counted by the counting arrangement and thus produce the wrong result. This is the reason why arrangements of this type are not suitable for being used in the modern technique of measuring, controlling, regulating and computing on the basis of digital values.

It is therefore one object of the present invention to provide for a counting apparatus which is absolutely safe against such disturbances by spurious signals.

It is a further object of this invention to improve conventional counting apparatus by providing means for causing the positive or negative direction of the changes of the monitored quantity to be transmitted without any delay through all the counting stages of the counting apparatus. In this manner the maximum counting speed depending upon the construction of the counting arrangemet stages will not be reduced substantially by the necessity for waiting, whenever the direction of the change steps varies, for all the counting stages to be switched by means of an auxiliary signal to a ditferent counting direction.

It is another object of this invention to further improve an apparatus of the type set forth by supplementing it with devices which overcome ditficulties that otherwise would arise if coincidence should occur between two identical pairs of input signals.

Another object of the invention is to provide for a position control arrangement comprising the features of one or the other of the above contemplated apparatus.

It is still another object of the invention to provide for an arrangement of the type set forth capable of converting input values x, y, 2 into increment signals Ix, Iy, Iz, respectively, and converting such input values into a sum Ax+By+Cz.

The invention utilizes certain conventional components or devices. For instance, multiphase signal generators are kown which deliver over a plurality of output lines sequences of signal element combinations representing a unit value change step or value increment occurring within a change of a variable quantity, thesignal sequences characterizing the positive or negative direction of the respective change step. There are known e.g. two-phase signal generators which issue on two output lines electrical yes-no signals which, if the change of the quantity takes place in one direction, represent a single change step of unit value in the following manner: a

opposite direction then the cycle of signal elements is reversed;

First line: no-no-yes-yes, i.e. O-O-L-L etc. Second line: no-yes-yes-no, i.e. O-L-L-O etc.

, ltshould be noted that signals furnished by. signal generators as mentioned above do not have to be electrical signals under all circumstances. It is quite as well possible to utilize for the same purpose optical, hydraulic or pneumatic signal pulses.

It is therefore another object of this invention to provide for a counting apparatus which is capable to utilize and to'process such signal sequences furnished by multiphasesignal generators in a particularly advantageous manner namely so that the arrangement operates in a way most closely resembling the operation of a mechanical speed reduction gear arrangement in which the direction of turn of the driven input shaft is automatically transmitted without any additional control means to all reduced speed gears of the respective gear train.

With above objects in view the invention includes an apparatus for forming the algebraic sum of digits each representing a unit value of increments occurring within a change in positive'or negative direction of a variable quantity, comprising, in combination, at least one multiphase signal generator means having a plurality of outputs and producing when actuated for each unit value of an occurring increment a cyclically repeatable primary combination signal of predetermined cycle duration composed of a plurality of different sequences of signal elements appearing at said dilferent outputs, respectively, said signal elements in said sequences thereof following each other in one sense when the respective increment takes place in positive direction, and in opposite sense when the particular increment takes place in negative direction; control means for actuating said signal generator means depending on the occurrence and direction of an increment of a variable quantity; and at least one logical circuit means having input means connected with said outputs of said signal generator means and having a plurality of outputs equal in number to that of said outputs of said signal generator means, said logical circuit means converting each of said primary combination signals into a secondary combination signal composed of the same sequences of signal elements as said primary combination signal, the cycle duration of said secondary combination signal being an integer multiple of that of said primary combination signal.

The invention further includes an apparatus for forming the algebraic sum of digits each representing a unit value of increments occurring within a change in positiveor negative direction of a variable quantity, comprising, in combination, at least one multiphase signal generator means having a plurality of outputs and producing when actuated for each unit value of an occurring increment a cyclically repeatable primary combination signal of predetermined cycle duration composed of a plurality of different sequences of binary code signal elements appearing at said different outputs, respectively, said binary code signal elements in said sequences thereof following each other in one sense when the respective increment takes place in positive direction, and in opposite sense when the particular increment takes place in negative direction; control means for actuating said signal generator means depending on the occurrence and direction of an increment of a variable quantity; one logical circuit means constituting a first binary counting chain stage having input means connected with said outputs of said signal generator means and having a plurality of outputs equal in number to that of said outputs of said signal generator means, said logical circuit means converting each'of said primary combination signals into a secondary combination signal composed of the same sequences of signal elements as said primary combination signal, the cycle duration of said secondary combination signal being twice that of said primary combination signal; and at least another logical circuit means constituting another binary counting chain stage having input means connected with said outputs of said first binary counting chain stage and having outputs equal in number to that of said outthe p puts of -said signal generator .means, said second-binary counting chain stage converting said secondary combination signal into a tertiary combination signal composed of the same sequences of signal elements as said secondary combination signal, the cycle duration of said teritary combination signal being twice that of said secondary combination signal.

In order to avoid the necessity of providing for special wave shapes of alternating voltage signals, it is advisable to base the construction of the arrangement according to the invention on the use of direct current by coupling e.g. certain bistable switching-elements required therein by direct current connections, which 'meahstha't betw'e'eh various c'ounting'c'liain stages no coupling means areprovided which as for instance capacitors or transformers only transmit occurring changes in. the condition, Ofone circuit component to the other, but the actual condition of one of these components is directly transmitted by direct current connection to the other component. Incidentally, also in the case" of hydraulic or pneumatic counting de'vicesa coupling of this type canbe" arranged for. v

For better'understandi'ng the basic concept of this invention it should be borne in mind that the signal generator mentioned above and further down in the specification and claims actually acts as an increment signal generator furnishing signals each of which represents an increment (positive or negative) of predetermined magnitude of a variable quantity as the latter varies. In the case of signal generators of the type referred to above a preselected small increment unit I is composed of four smaller fractional increments of the magnitude 1/4 which may follow one another in'positive as well as in negative direction, Each increment unit I is represented by a full cycle of four signal elements, each element being a pair of signals appearing two-phase generator. For instance, a positive fractional increment may be represented by a change of condition from L, O to L, L or from L, L to O, L, and a negative fractional increment may be represented by a change of condition from L, O to O, O or from L, L to L, 0.

Similarly the counting apapratus referred to above would function as an increment adder so that as a result of such addition for instance a mechanism may be controlled so asQto undergo changes of position exactly corresponding to 'the variation of said variable quantity the positive and negative increments whereof are represented by said signals. Similarly, by integration of such increments i.e. corresponding processing of the respective signals an indication of the value of said variable quantity at any given moment or the position at any given moment of a moving element changing position depending upon or in line with said chage of said variable quantity can be obtained.

It will be seen that a counting apparatus according to the invention does not count exclusively the individual switching operations by which changes between yes and no condition is produced at the input lines. Instead the apparatus according to the invention counts combination signals composed of sequences or cycles of different conditions or signal elements appearing at the different input lines. Hereby the great advantage is achieved that spurious signals which otherwise might imitate the switch from a yes condition to a no condition or vice versa applying to one of the input lines, cannot be counted. In this manner the above mentioned object of the invention, namely avoiding the effects of spurious signals, is reached.

In order to solve the existing problem, for two-phase input signals the following system of equations in terms of Boolean algebra can be written:

in the two output lines of the .by by A ML, and B or 1 respectively, and if one avails oneself of the possibilitythat the output transistors act in pairs as flip-flop elements with outputs A or A and B or B respectively, then one obtains the following simultaneously valid simplified pairs of equations:

For definingthe logical connections between the partial stages of the individual counting chain stages this simplified system of equations will be used further below in this specification and in the claims.

It is known to those skilled in the art that logical circuit conditions of this type can be embodied by parallel arrangements of series-connected relay contacts or by corresopnding combinations of AND and OR gate circuits arranged at the input of electronic, hydraulic or pneumatic flip-flop devices. 1

In accordance with the invention, a counting chain composed only of binary counting stages'rnay be converted with the aid of comparatively simple additional means into an apparatus for counting decimal digits in their respective decimal order positions. Assuming that the decimal digits are represented each by a binary code term composed of four binary elements, it is only necessary to supplement each group of four consecutive binary counting chain stages constituting a tetrade assigned to deal with a particular decimal order of decimal numbers, by adding an auxiliary control or change-over switching stage which'serves to select out of the sixteen possible element combinations of the four binary counting stages only ten and employs these ten combinations in such a manner that a suitable binary code for the decimal digits to 9 is established.

For instance, in the case of a two-phase binary counting chain composed of tetrades (as explained above) in each tetrade between the first and second binary counting stage an auxiliary control stage constituting a twophase switching device may be inserted which operates in the following manner. It responds to the input signals A and B applied to the particular tetrade, to the output signals A and B of the first binary counting stage, and to one of the output signals B and B of the third or fourth binary counting stage of that tetrade, and applies to the second binary counting stage during each sequence of ten complete combination signals A and B first two cycles of the output signal combination A and B of the first binary counting stage, thereafter six cycles of the input signal combinations A and B and finally again two cycles of the output combination signals A and B of the first binary counting stage. For obtaining this result it is suflicient if the two-phase switching device or auxiliary control stage satisfies, as far as the signal combinations A and B applied to the second binary counting stage are concerned the following conditions defined in terms of Boolean algebra:

In this manner one arrives at a very convenient and advantageous binary code for decimal digits wherein the combination of the operative (yes or no) conditions of the bistable circuit elements A A A and A respectively, associated with A-phase of the signals and provided in the four counting stages of each tetrade correspond to the ten decimal digits 0 to 9, as'follows:

Weight Circuit Element It can be seen that this binary code meets all the conditions that have been set up to now for codes ofthis type representing decimal digits:

1) The binary numbers increase stepwise monotonously, i.e. the value of the binary numbers considering the weight given to the individual bits increases by units.

(2) If in any one of the binary representations of a decimal digit each L is converted into an O, and each 0 is converted into an L, the resulting binary number represents the nines-complement of the respective decimal digit.

(3) In view of the convenient weight allocation to the individual binary order positions the code is easily readable and its indications can be converted correspondingly easily into analog values.

(4) The binary digit in the first order position from the right indicates clearly whether the represented decimal digit is an odd or an even number because 0 corresponds to even numbers and L corresponds to odd numbers.

(5) The binary digit in the first order position from the left indicates clearly whether the represented decimal digit is smaller than 5 as indicated by O, or larger than 4 as indicated by L.

(6) The coded terms may be considered as fourelement binary numbers and may be added as such.

If this is done in an adding device a correction only in one order position will be required when the output of the adding device is applied to a digital-analog-converter.

In certain cases' it may be desirable to count in a counting apparatus according to the invention the algebraic sums of two signal sequences furnished by two signal generators, e.g. in order to continuously form the variable difference between a program value of a certain physical quantity to be controlled, on one hand, and a variable actual value of that quantity as furnished by the second signal generator, on the other hand, so that said algebraic sum or a corresponding signal may be used for controlling or adjusting the particular physical quantity after the difference value found by the operation of the apparatus has been converted into an analog control or adjustment value. This can be achieved in accordance with the invention if a multiphase adding device is used which in its function resembles that of a mechanical differential gear. Accordingly it is for instance possible to connect the output lines X and Y of a two-phase adding arrangement (which has its inputs connected to the pairs of outputs A, B and C, D, respectively, of two-phase signal generators) with the two inputs of a two-phase counting apparatus according to the present invention. All that is necessary is that for instance the two-phase adding arrangement must comply with the following conditions in terms of Boolean algebra:

this specification the term counting stage is used it is not intended to have included means for indicating the result of a count, because such counting stages may as well be considered as being binary storage arrangements for storing certain values in binary form because it is well known that such stored information may be transmitted or applied to other devices by conventional means.

It will be understood that in a system as contemplated pairs of signals A, B and C, D may be delivered by two signal generators simultaneously and such coincidence, particularly if the pairs are identical, would create a serious difficulty since the counter or adder would not know in which direction to move. It will be shown that by deriving somewhat delayed signals A B C D, from A, B, C, D, respectively, and by processing pairs A, A B, B;,,; C, C D, D a proper functioning of the system can be achieved.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings, in which:

FIG. 1 is a schematic circuit diagram illustrating a basic embodiment of the invention including one example of a two-phase electrical signal generator and of a twophase binary counting stage;

FIG. 1a is a diagrammatic illustration of a modification of'the arrangement according to FIG. 1 and including a plurality of counting stages in series-connection;

FIG. 2 is a time diagram illustrating the relation between input signals applied to the counting stage of FIG. 1 and output signals furnished thereby;

FIG. 3 is a schematic diagram of a three-phase electrical signal generator otherwise similar to that which is shown in FIG. 1;

FIG. 4 is a schematic circuit diagram of a two-phase binary counting stage comprising a bistable flip-flop circuits instead of the bistable relays provided in the arrangement according to FIG. 1;

. FIG. 5 is a schematic circuit diagram illustrating a further development of the invention in the form of a binary counting chain comprising a tetrade of seriesconnected counting stages and an auxiliary control stage; FIG. 6 is a schematic circuit diagram illustrating an alternative form of the auxiliary control circuit included in FIG. 5;

FIG. 7 is a schematic circuit diagram illustrating a combination of two signal generators furnishing twophase signals to a two-phase adding arrangement which, in turn, issues such signals representing the sum of the first mentioned two-phase signals to an adding arrangement e.g. according to FIG. 5;

FIGS. 7a and 7b aretime diagrams illustrating the sequence and combination. of signals as they may be processed by arrangements according to FIGS. 5 and 7, respectively;

FIG. 8 is another diagram illustrating the cooperation of an arrangement according to FIG. 7 with two binary adding chains includingeach a tetrade of adding stages;

FIG. 9 is another schematic circuit diagram illustrating an electronic adding arrangement suitable to replace the adding arrangement of FIG. 7;

FIG. 10 is a schematic circuit diagram of a first portion of an electronic adding arrangement according to the invention, modified for being insensitive to coincidences of two identical pairs of input signals;

FIG. 11 is a similar diagram illustrating a second portion of said arrangement;

FIG. 12 is a schematic diagram of a servomotor arrangement for position control according to the invention; and

FIG. 13 is a diagram of an arrangement according to the invention for producing a value of the form 8 derived from independently variable input values 3a, and z.

Referring now to FIG. 1, by way of example one type of a two-phase electrical signal generator IG is illustrated which includes a wiper contact arm K carried by a shaft W for rotation both in counter-clockwise direction +04 or in clockwise direction -a as may be desired. It is to be assumed that the shaft W is rotated by means not shown in accordance with positive or negative changes of some variable quantity to be monitored. A complete rotation of the wiper arm K would correspond to the unit value of a change step. The arm K is connected to the positive terminal of a source of direct current as indicated. During rotation the wiper arm K cooperates with two semi-circular stationary contact bars K and K which are offset against each other as shown. The contact bars K and K are connected to ground via respectively associated relay coils A andB It will be understood readily that the two relay coilswill be alternatingly energized and de-energized while the wiper arm K rotates in counter-clockwise direction which corresponds to positive changes of the variable quantity to be monitored. The periodic energizations and de-energizations of the relay coils A and B respectively, are illustrated graphically by the diagrams D and D respectively, of FIG. 2. One complete rotation of the wiper arm K constitutes a period P as shown in FIG. 2. In view of the construction of the contact bars K and K the diagrams D and D are identical with each other, however the second one D leads the other in phase, the phase difference being A of a period P Thus it can be seen that if the directional angle a of the slider arm K changes in positive direction i.e. by counter-clockwise rotation the two-phase'signal generator IG will cause energization of its output relay coils A and B respectively, consecutively in such a manner that, considering the relay coils A and B as outputs of the generator, during each cycle of the generator a combination signal appears at these outputs, the combination signal being composed of two sequences of signal elements as indicated by:

wherein 0 represents tie-energization and L represents energization of a relay coil, each pair of these symbols representing the simultaneous condition of the two relay coils A and B Each such signal sequence constituting one combination signal corresponds to one complete turn of the shaft W It will not require detailed explanation for understanding that in the case of a rotation of the shaft and wiper arm K in the opposite i.e. negative direction the resulting combination signal would be It can be seen readily that the two combination signals differ from each other and that thus these combination signals directly indicate by their own nature whether they are produced by a positive or by a negative change of the variable quantity being monitored.

It should be noted that other signal generators may be used. For instance optical-electrical two-phase signal generators for indicating angular variations are known which produce such cyclic combination signals representing very small angular steps of a rotary member and which could be used for monitoring or measuring rotary movements in a manner similar to that described above with respect to the rotary signal generator IG.

It is Well known that a two-phase system can be converted into a three-phase system and vice versa. As an example FIG. 3 illustrates a three-phase generator 1G which is constructed and operates in a manner quite similar to that of the generatorof FIG. 1, but which comprises three circular contact bars K K and K5, each extending over an arc of and being offset angularly 60 against each other, with a wiper arm K cooperating therewith and carried by a shaftW During one complete turn of the arm K the three relay coils A B and C respectively, are energized alternatingly. Of course, if not a three-phase adding arrangement is supplied by the output of this signal generator, the output signals from the three-phase arrangement of FIG. 3 could be converted by conventional means into twophase signals which then could be processed in the manner described in reference to FIG. 1.

Returning now to FIG. 1, the two-phase binary counting stage illustrated thereby will now be described. This binary counting stage serves to form the algebraic sum of positive and negative, as the case may be, signal sequences A and B produced by the signal generator 1G by means of energizations of the relay coils A and B The counting stage comprises two output relay coils A and B constituting electrically controllable bistable circuit components. The relay coils A and B are connected between a positive terminal of the above mentioned direct current source and ground by a network which comprises contacts a b and 17 operated by the generator relay coils A and B respectively, and contacts a a a b b and b actuated by the relay coils A and B respectively. It can be seen readily and it will be explained further below that on account of the circuit details of FIG. 1 the two relay coils A and B will be energized in a manner illustrated by the diagrams D and D respectively, of FIG. 2, provided that the relay coils A and B of the signal generator are operated in accordance With the diagrams D and D respectively. Thus, the two output relay coils A and B are actuated in a two-phase combination signal cycle which corresponds exactly to that of the signal generator relay coils A and B respectively, as far as the signal sequence within each cycle is concerned, while the period duration P of the output combination signal is twice as long as that of the period duration P of the input combination signal. This amounts to a step-down ratio of 2:1 between the respective counting speeds.

The energization of the relay coils A and B i.e. the output signal production of the counting stage, in response to the actuation of the signal generator relay coils A and B respectively, is illustrated by the following chart:

Energization of Relay Coils Rotation of Kg Positive (counterclockwise A0 B0 A1 B1 First turn:

O O 0 0 Starting condition as shown in Fig. 1. 0 L O 0 Kg on Ks: B energized, h and bug without effect. L L O L Kg on Ka and KbIAn and B0 energized,

B1 energized via an, boz, an and Wm. L O O L Kg on KB:B1 holds itself via bu. Second turn:

"O O L L Kgvofi: A1 energized v1a A0, b b1: and

al- 0 L L L A holds itself via an and W81.

L L L 0 B1 is shunted via a0, boa, an and Wm. L O L 0 Third turn:

O O 0 0 A; is shunted via a), hm, b and W111- Rotation of Kg Negative (Clockwise) First turn:

0 0 O 0 Starting condition per Fig. 1. L O L O A; energized via a bog, h and W L L L O A; holds itself via a and W. *O L L L B1 energized via a bar, 312 and Wm. Second turn:

O O L L B; holds itself via his and Wm. L O O L A1 shunted via at, boz, bu, and val- L L O L O L O 0 Bl shunted via an, bn, 812 and Wm. Third turn:

It can be seen from the above that spurious signals which may simulate an energization of the relay coils A or B or which might prevent the indication of an energization of one of these two relays, may be capable of erroneously changing the operative condition of the output relay coils A or B "but as soon as the spurious signal vanishes the respective relay coil A or B returns to its previous condition.

For instance, if during operation at the moment marked at the beginning of the second turn a wrong A-impulse should be received i.e. the relay coil A is de energized too late, then in the wholecircuit arrangement the condition existing in accordance with the preceding line of the chart would continue until finally the erroneous or wrong signal impulse vanishes. Then ll'fl'. mediately the normal operation would take effect. If, on the other hand, an erroneous or spurious A-impulse should appear at the moment marked by then the relay coil B would be shunted too early as indicated in the next following line i.e. this intended condition would be reached too early, but as soon as the erroneous A-impulse or signal has vanished, the normal course of operation would take place again. A similar condition would develop under similar circumstances at the moment marked It will be understood that in view of this behavior the two-phase binary counting arrangement as illustrated and described displays a very substantial insensitivity to disturbances by spurious signals.

It can be seen further that in a two-phase binary counting stage as described above not the occurrence of a single impulse but the occurrence of a complete cycle of four partial steps or a combination signal composed of a sequence of four signals are counted, and that the positive or negative direction of the changes to be counted and represented by the particular signal sequences in the combination signals is automatically and immediately also transmitted to the outputs of the binary counting stages, however all this with a reduction of the speed of signal sequence or increase of the cycle duration at the ratio of 1:2, i.e. in a manner comparable to a mechanical step-down gear transmission.

It now the binary counting stage illustrated by FIG. 1 is supplemented by at least one more similar binary counting stage having output relay coils A and B and if said second binary counting stage contains relay contacts actuated by the relay coils A and B in the same manner as in the first stage the contacts actuated by the relay coils A and B are operated, then a two-phase binary counting chain of a plurality of counting stages is established of which each stage cooperates with the P next following stage in the same manner as the primary signal generator 16 cooperates with the first binary counting stage illustrated in FIG. 1.

Various ways are open for deriving from the information stored during operations in the binary counting stages also an indication of the count performed. One simple expedient would be for example to connect, as illustrated in FIG. 1, signal lamps S S in parallel with the relay coils A and B, respectively, and similarly signal lamps S and S in parallel with the relay coils A and B respectively. These lamps would always indicate whether the respectively associated relay coil is energized or not which would mean whether a signal is momentarily stored in the arrangement by such energization of a coil. As mentioned above, energization of one of these relay coils represents the condition L and deenergization of such coil represents the condition 0.

To elaborate on this idea FIG. 1a illustrates diagrammatically a signal generator IG in connection with a twophase counting chain comprising six stages after the first stage represented by the relay coils A and B Next to each of these stages a signal light is shown and designated S -8, By way of example, some of the circles representing the signal lamps are shown cross-hatched which means that these lights are on which would represent that the respectively associated relay coil A A A and A is energized. The respectively corresponding L and O conditions are marked above each one of the signal lamps and stages. Below the arrangement is marked the Weight which may be assigned to the symbol L in the various stages or in the sequence of their appearance in the consecutive 11 positions. In this particular case the information stored in the arrangement would be represented by the binary number LOLLOOL which would correspond, in accord ance with the indicated weights, to the decimal number 77.

The binary two-phase counting stage of FIG. 1 constitutes, on account of the relay coils A and B coupled by direct current connections with the relay coils A and B, respectively, and the respective contacts on arrangement having two inputs A and B and two outputs A and B which in accordance with Boolean algebra satisfies the following conditions:

In consideration of the arrangement according to FIG. 1, in the above given system of Equations A and B represent the actual operative condition at a given moment of the relay coils forming part of the impulse generator 16, A and B represent the actual operative conditions at the same moment of the relay coils forming part of the first binary counting stage. On the other hand K and B as well as K and B represent the opposite operative conditions of the respective relays which do not exist at such given moment mentioned above.

While the above remarks concern an impulse generator including relay coils A and B it will be understood that it is known to those skilled in the art to construct twophase impulse generators and to arrange such a generator for cooperation with a binary counting stage on the basis of the circuit logic applied to FIG. 1, without the use of relays.

FIG. 4 illustrates a two-phase binary counting stage which is based on the same circuit logic and has the same effect in operation as the above described counting stage. However, the stage according to FIG. 4 comprises as electrically controllable bistable circuit components a plurality of flip-flop stages of conventional type, each including two transistor gate circuits T and T and T and T and having output lines A and K and B and B and being provided each with two input lines A and K and B and B The functional interconnection of the components of this circuit in accordance with the above listed Boolean conditions is effected by means of conventional AND gates U and OR-gates Or composed of diode combinations. It should be noted that in this circuit arrangement equipped with PNP transistors the no conditions would correspond to a switched-off condition of the particular line (voltage 0) while the yes condition would correspond to the presence of a negative potential of at least 6 volts in the particular line.

It is evident that purely electronic counting Stages of this type entail a substantially higher counting speed than relay-equipped counting stages according to FIG. 1. It should be noted that in the arrangement according to FIG. 4 the inputs A and K and B and 3 have the same function as therelay coils A and B respectively, in the arrangement according to FIG. 1 while the outputs A and K and B and B have the same function as the relay coils A and B respectively, of FIG. 1. For the sake of completeness the diagram of FIG. 4 contains also a resetting line R passing through the whole length of the arrangement by means of which each binary counting stage may be reset to idle condition (O-condition).

It can be seen that the diagram of FIG. 4 does not include an impulse or signal generator but such a signal generator e.g. 1 as described and illustrated above may be connected with its output to the input A B of the stage according to FIG. 4. One of the lines of each pair thereof is always carrying a certain potential (L-condition) while the other line of the individual pair does not carry a potential (O-condition).

It has been mentioned further above that also threephase signal generators according to FIG. 3 may be used. Analagously, counting chains comprising in each counting stage three direct current coupled bistable circuit com ponents can be provided in which the bistable components are so interconnected logically that each counting'stage again is able to act as a three-phase signal generator; however with a period duration twice as long as that of a preceding stage. I

FIG. 5 illustrates an arrangement'which comprises in addition to a signal generator IG a binary counting chain including a tetrade of four counting stages BS BS BS and BS; with the interposition of an auxiliary control stage HST between the first and the second counting stage. For the sake of simplicity details of the generator and of the individual counting stages are not given, particularly the individual relay coils referred to above are not illustrated. The outputs A and B of the generator IG may be at a given moment either current carrying (L-condition) or without current (O-condition) so that in the manner described above for the combination signals, e.g., the sequence OOLL on output A and the sequence OLLO on the output B, are possible. The binary counting stages may be constructed according to FIG. 1 or according to FIG. 4. Thus they may contain relay coils A B A B etc. which may be energized or de-energized and thus represent L-condition or O-condition.

The auxiliary control stage HST comprises according to FIG. 5 two bistable switching elements nar'nely relay coils B and B which actuate each a pair of contacts b and 17 respectively. These relay coils B and B are energized only when the respectively associated outputs B of the stage BS and B of the stage BS; carry a predetermined potential. The control stage HST has four inputs respectively connected with the outputs A and B of the generator IG and with the outputs A and B of the first counting stage B5,. The control stage has further two outputs A and B which are connected with the inputs of the second counting stage The output lines A and Bf of the auxiliary control stage HST which at the same time constitute the inputs for the binary counting stage BS are interconnected with the above mentioned inputs by the contacts of the above mentioned relays in accordance with the following Boolean conditions:

This means that the outputs A and Bf of the auxiliary control stage, i.e., the inputs of the second binary counting stage BS are connected either with the outputs A and B',,, respectively, of the signal generator IG, or with the outputs A and B' respectively, of the first binary counting stage BS depending upon whether at least one of the outputs B or B carries an operating potential or none of them does this. In other words, as long as the relay coils B and B are not energized, the conditions of the outputs A and Bf correspond exactly to the conditions of the outputs A and B respectively, of the first binary counting stage BS As soon as relay coil B is energized (but B is not), or vice versa, i.e., either the connecting line B or the connecting line B carries an operative potential, the outputs A and Bf are connected directly with the outputs A and B respectively, of hte signal generator IG. Also when both relay coils B and B are simultaneously energized, the outputs A and Bf are connected with the generatOr outputs A and B respectively.

Thus it can be seen that FIG. 5 illustrates a tetrade of four binary counting stages plus one auxiliary control stage which arrangement is capable of storing any one of the decimal digits 0-9 in binary coded form. Thus the entire arrangement according to FIG. 5 can be used as a ,countingarrangement for one particular order of a a In the following column HST the signals appearing at decimal number. t a i the outputs A and B respectively, of the auxiliary The following chart will serve to illustrate the operacontrol stage, are listed in relation to the signals in the first tti'on of antarrangement according to FIG. 5. 1 two columns. It can be seen that the signal sequence ap- "fbecmir "no a 13s; f HST BS2 Bs, BS4

: A0 7 A1 I B1 Ar Bf A2 B2 A3 B3 A4 I B4 0 o -o l o 0 0 o 2 o 0 o o p 0 Q"L-' o; o o 0 0 o o 0 o o L L o L o L o 0 o o o o L0 'O'L- o L o o o 0 0,0

1 0 0 L L L g L o 0 o' 0 o L L L L L o L p 0 o o 0 L .L L 0 L 0 0 L o o o o L o L o L o o L o 0 o o 0 0 0 o p Q 0 L L Q L o o 0 L o 0 0 L L L 0 L o o L L o L L L L 0 0 L 0 o L o 0 L L 0 L o 0 L 0 o a. o 0 I L L 0 0 o o L L 2 L o L 'L 'L o L 0 o L L 0 L L L g L o L L 0' L L L 0 L L 0 L o L o 0 L L L 0 L 4'. o l o 9' 0 o o L L L 0 2 L o L o o o L L L L o o L L L 0 L g L L L o L 0 o L L 0 o L L o L o L 0 o L :5 o o w L L o 0 L 01 0 o L L o 0 t L L 0 L o o 0 o L L L 0 L o L L 0 V L 0 0 L L L o L 0 L 0 0 L o 0 L L 6 1 0 0 '2 o 0 o L L 0 L L L o L 0' o 0 L L L o L L L L L 0 .L L L L o o L L L L 0 o L L i 0 L 0 0 L L L 1 o o L L o -o 2 0 L L L or 0 L' L L 0 L 0 0' L L L o L L L o L L o L L L L o L o L o L 0 o a L L L L 0 s o o 9 0 0 o L L L o L o o L 0' o 0 0 L L L 0 L o L L l 0' L o L L L L o L o L 0 0 L 0 L L L L L o L o 9 0 0 L L L L L o L 0 L 0 o L L L L L L o L 0 L o L L L 0 L 0 L 0 L 0 L o L 0 L 0 L 0 L o L 0 L o In the above chart the first column marked 16' shows pearing at the output of the control stage is either equal in vertical arrangement a sequence of ten combination to that issued by the first 'counting'sta'ge'BS (for decisignals following each other in the sequence of increasing mal digits 0, 1, 8 and 9) or it is equal to those issued by decimal digits as marked at the left hand margin, each the signal generator IG (for decimal digits 2, '3, 4, 5,6 combination signal being composed by two sequences of and 7). These identities are marked in the chart by versigna1s'A' and B appearing at the so marked outputs 65 tical lines along the respective combination signals-.- The ile, as energization and de-energization of the relay coils remaining columns BS BS and-BS contain the corre- A and B respectively of the generator IG. The indivisponding combination signals appearing at the outputs of dual signal sequences are those specified further above. the remaining counting stagestor represented by the enerof the signals and cycles in-the column IG.

The' next column BS contains the signals appearing at gization of the respective relay COiIS'Ag B A B A the output of the first counting stage in the form-of ener- 70 B respectively. a w

gization of the relay coils A and -B As can be seen, in Assuming that in the arrangement according to FIG. 5 accordance with the explanation given with reference t0 indicating lights are connected in parallel with the relay FIG. 1 and 2 the -duration of the signals andsignal cycles coils A A A and A '-of the four counting stage in appearing in column BSfis doubled against the duration a manner similar to that illustrated by FIG. 1a, and if i it is further assumed that energization and deenergization of the relay coils just resentation of the binary digit L or '0, respectively, then it can be seen that as the operation would proceed from decimal digit up to the decimal digit 9, with each counting" step a binary n urrib'er is stored or indicated in the tetrade of four binary counting stages as indicated by underscorin'g' in the columns BS -BS the first'signal (O or L) of each signal sequence in the colurnn designated A A A and' A4. ItWill' be found that the"und'er scored group of four binary digits'in each horizontal row' corresponds exactly to the binary code for decimal digits given further above and in each row represents the nu-" meric'al value of the correspondingdecimaldigit marked atthelefthandmargin. p w

FIG. 6 illustrates an alternative for the auxiliary control stage HST of FIG. 5. Instead of relays-including relays coilsand relaycontacts shown in FIG. 5", the control stage according to FIG. 6 is a purely electronic arrangement comprising AND-gate c1rc v said gate circuitsbeing composed in well known manner of diode circuit arrangements which influence bistable flip-flop .circuits .comprising transistors T T and T Twas shown. v t The operation of the auxiliary control stage according to FIG. 6 is entirely the same as that of the circuit or stage shown in FIG. 5. The outputs A A and B 5 respectively, are controlled by the respectively associated pairs of control transistors mentioned above. In each pair of control transistors the condition of conduc tivity of one of the transistors is always opposite to that of the other transistor, i.e. the condition of conductivity of the control transistor T is the opposite of the condition of the associated transistor T and vice versa.

The reference letters designating the various inputs and outputs are purposely the same which have been used in FIG. 5 so that under these circumstances it can be seen that the circuit according to FIG. 6 also satisfies the condition in Boolean terms given above in reference to FIG. 5.

FIG. 7 illustrates a further development of the invention which combines in one pair of outputs X and Y additively or subtractively the two-phase combination signals furnished by two separate signal generators 1G and 16 respectively, at their outputs i.e. by energization of the relay coils A, B and C, D, respectively. A twophase adder ADD is interposed for this purpose between the signal generators 1G and 1G and the outputs X and Y The signal generators may be of the same type as illustrated in FIG. 1. The function of the two-phase adder is the exact counterpart of a mechanical differential gear of conventional type having two input shafts and one output shaft. The rotational movements of one input shaft of the gear corresponds to the combination signals appearing at the outputs A, B of the first signal generator 16 while the rotary movement of the second input shaft correspond to the combination signals appearing at the outputs C, D of the second signal generator'lG- and the resulting rotary movements of the output shaft of the differential gear correspond to the output signal combinations which appear at the outputs X and Y of the adder.

As can be seen from FIG. 8 explained further below the output signals appearing at the outputs X and Y of the adder may be applied to a binary counting chain similar to that shown in FIG. 5. Arrangements according to FIGS. 7 and 8 are useful and advisable for determining by a counting or algebraic adding operation variable difference-values between a variable target value or predetermined value of a quantity and a likewise variable actual value of that particular quantity to be monitored. The resulting variable difference value may also be counted or algebraically added in a two-phase adding apparatus according to FIGS. 1 or 4, and may, if desired, be converted into an analog value so as to be utilized as a control value actuating an adjusting or regulating device whereby the mentioned corresponds to the rep actual values of the res tive quantity are automatically its U and QR-gate circuits Qr,

mined or target value thereof.

The logical interconnection of the outputs X Y with the adder inputs i.e. the Band C, D, respectively, of the signal generators TG' and "I G" ',"r'espectively, in hetWmph aa erjADD st u i ing e y soi X, .Y and respectively associated relay co'rli acts-ig b ii, as shown in FIG. 7, satisfies the follow'ng conditions in term's'of-lBoolean=algebra:

The same would apply also to an interconnection ac- -In-order to explain the-operationwof the arrangement according toFIG. -7 reference'isarnade to the..diagrams-..o-f P168711 7b 2 v a,

The diagram of FIG. tion because actually the diagram of FIG. 7a illustrates rather the operation of the basic arrangement according to FIG. 1. In FIG. 7a the abscissa is time, while the ordinates of the graph G are shown as increasing and decreasing by uniform increments dy so that the graph G illustrates the above mentioned changes of a variable quantity as time passes. The ordinate p corresponds to one complete rotation of the wiper arm Kg of the signal generator according to FIG. 1 i.e. to a combination signal composed of a sequence of four signal combinations numbered 1, 2, 3, 4 in FIG. 7a. However, while FIG. 2 is based on the assumptionthat thevariable quantity being monitored changes onlyinone direction and continuously at the same speed, it can be seen that the more general condition illustrated by the graph G .-illustrates the changes of the variablequantity occurring at varying speeds or intervals and not always occurring in the same direction. I

Above the graph G two horizontal diagrams are shown which illustrate the signal sequences D and D5 corre-- the top of FIG. 7a will result. This means that at any time during the operation the momentary magnitude of the monitored quantity relative tov a' starting value 0 will be indicated.

It can be seen clearly from this diagram that each c'hange of the outputsignals D and D ,'respectively, between 0 and a reference value not only constitutes the indication of a change step dy of'the' monitoredwquantity. represented by thecurve G but that it also. indicates in which directionsuc'hchange step has taken placex-The rule is simply that as'long as theindividual-signals D' arid-D change altern'atingly i.e.: one after the-other,- the direction of the particular change step remains unchanged i.e. either positive or negative-asthe case may be. However, whenever one of the two signals, either'D .or D .changes in-sucession between'tland its reference value or back to 0'witlrout theo'ther signal having changed in the same manner meanwhile, then this condition 'indicates that the direction of the change step has changed;

The diagram of FIG. -7 b' is"constructed 'on the same principle except that 'i'tc oncerns" and illustrates 'the operat 7a is presented as an'introducare .shown which illustrate the positive and negative 'changes'of two variable quantities which changes 'are'represented by the output signals A, B and C, D, respectively, issued'by the signal generator 1G and 16 respectively, and illustrated accordingly by.the diagrams sodesignated along the top of FIG. 7b. At the outputs X and Y of the adder ADD will then appear signal sequences as illustrated by the diagrams X Y of FIG. 7b. This sequence of signals corresponds exactly to the third graph Gi+G2 shown in the lower portion of FIG. 7b and representing at every distance the algebraic sum of the ordinates of the graphs G and G g It can be seen that any change step of either one of the twovariable quantities being-monitored is truly represented in the output signals X Y concerning the occurrence of the individual step as well as concerning its positive or negative direction. It can also be seen from FIG. 7b that if one of the signal generators is standing still, the output signal of the other signal generator appears unchanged at the outputs X Y Finally FIG. 9 illustrates only the alternative to the two-phase adder ADD of-FIG. 8 by replacing the relay 3 and contact arrangement of FIG. 7 by anequivalentelectronic arrangement comprising ill a manner similar to that described with reference to FIG. 6: electronic adding circuits composed of AND-gate circuits U and OR- gate circuits OR and two flip-flop stages Y and Y, 'Y

The function of the electronic adder according to FIG. 9 is entirely analogous to that of the relay type adder of FIG. 7 and therefore evidently does notrequire a detailed=- description.

-It will be noted that in an the'FIGUR l ES L9 with :h

exception of the diagrams FIGS. 7a and 7b signal lights are shown without detailed description, but correspond ing to the signal lights shown in FIGS.;1 and 1a and for the same purpose as described in reference to the last mentioned illustrations.

For the sake of completeness the followingmay be added. In the arrangement according to FIG. 4 the binary 4' counting stage illustrated thereby and for all the con-.

secutive similar counting stages provided that 'acounting chain of such stages is formed, a common re-set line R is provided by means of which all the counting stagesof the chain may be re-set to 0 position simultaneously and jointly-However the arrangement could be modified without difiiculty in such a manner that a second re-set input is provided for placing bothfiip-flop components into yes condition (L-condition). Then it-would be possible in a conventional manner to set by means of a pres etting arrangement the entire counting chain to any desired numerical or binary storage content after which ment which is assumed to and T T respectively.

essary to describe these B and C, D, in other words, an arrangement which opcrates properly even in thecase of such 'a'coincide'nce'f FIG. 10 illustrates one portion of such'an arrangebe supplied with input signals A, B, C, D, from the'i-mpulse generator as shown at the left hand of FIGS. 7-9. The arrangement according to FIG. 1-0 comprises; four identical "circuit"arr angements N N N and N however, of thesecircjuit arrangements the last three'tnentioned above are shown only in block form because theyare entirely identical with" the circuit arrangement N}, which is shown in complete detail. FIG. 10 shows the inputs ofthe above mentiq i d signals A-D furnished by the two'increment signal generators.

Each of these circuit arrangements comprises ,a delay circuit N of-conventional type which derives frofn'the respective input signal e.g. from signal A a secondary signal A (B C and D respectively, in the other circuits) delayed a predetermined interval after the respective primary or original signal. The now existing pair of signals e.g.;A and A is applied both to a diode type AND-gate .U and to a diode type OR-gate Or as shown.

. The output signals of these gates are symbolized by A+ v. and 2+] =A.A, respectively, and are taken to two flip-flop stages F and F respectively of conventionaltypeandcomprising each two transistors T T It does not appear to be necconventional circuits in detail. It will be readily understood by those skilled in the art that by operation of the just described circuit arrange- "ments N ,-N N and N each of these circuit arrangementsqproduces a pair of auxiliary signals Q, S, P, W, R, T, V, Z and their negated or inverted values in such a manner thateach of these auxiliary signals is defined 5 by a corresponding logical linkage with the above men- -tioned original input signals A, B, C, D and with the corresponding delayed auxiliary signals Av, B C.,, D,,, respectively as indicated herebelown Q= v v v I S=B+B,, T=F+F =1TJ 71 W=D+D Z=7J+F :DTE v The corresponding negated values are formed in an analogous manner.

The above mentioned outputsignals of the circuit arrangements shown in FIG. 10 are fed-as they occur into 7 asecond portion of the arrangement as illustrated by FIG. 11. The arrangement according to FIG. 11 iscomposed as can be seen of a plurality of AND-gates U constituting a first OR-gate Or and another plurality of the counting procedure would start from this stored content in forward or rearward direction, i.e., additively or su'btractively depending upon the positive or negative nature and the number of combinationsignals introduced into the arrangement. s FIG. 8 referred to above hardly requires further explanation in view of the above. However, it should be noted that FIG. 8,sh0ws an arrangement comprising several counting stages of which two stages DS and DS are shown. These stages act in the manner described above as generators for two-phase signal sequences X and Y or X "'and Y respectively, of thesarne type and signal sequence as the input combination signals X and Y with the only difference that the cycle durations..are in-. creased at the ratio of 1:10 and 1:100, respectively.

As mentioned further above it could occur that in the operation of arrangements according to FIGS. 7-9 the two separate signal generators 1G and 16 furnish identical signals coincidently in which case of course difficulties would result because there would not be any certainty.as to which one of the circuit components would respond to which signal. FIGS. 10 and ll illustrate an improved arrangement according to the invention which is insensitive to coincidence of pairs of input signals A,

AND-gates U constituting a second OR' 'gate Or "as illustrated. The various AND-gates of FIG. 11 are connected with the outputs P -Z, respectively, of'the arrangement according to FIG. 10 as indicated in FIG'. 11;"For the sake of simplicity of the illustration most of the AND- gates are shown only diagrammatically exceptfor the upper two gates in the right hand column thereof where the conventional structure of these gates is illustrated in detail. The above mentioned OR-gates Or and Or" deliver their output signals into conventional fiip'-flopcircuits F and F respectively. The flip-flop circuit "F is illustrated in detail while the other circuit F is illustrated onlyv diagrammatically because it is "otherwise entirely identical with F At the outputs of these flip-fiopwircuits appear in operation of the arrangement the desired .outputsignals X and Y or their respective negated values These or analogous linkage equations determine the 

